Agathaumas Cope

E. D. Cope., 1892, Fourth note on the Dinosauria of the Laramie., The American Naturalist 26, pp. 756-758 : 758

Agathaumas Cope —

Professor Marsh (Amer. Journ. Sci. Arts, 1892, p. 83) endeavors to show that this genus differs from any of those described by him by quoting characters from my description of the type specimen . Since my last description of that genus was published (1875), I have studied part of a skeleton obtained by Dr. J. L. Wortman in Dakota, of which the parts are undistinguishable from those of the Agathaumas silvestre . These include an ilium in much better preservation than that of the type, and I am enabled to correct some of the statements contained in my original description. I stated that there is no facet for the pubis at the front of the acetabulum. The surface at this point is broken in both of my specimens, but it is altogether probable that the structure at this point does not differ from that of the allied forms. The ischiadic suture is in like manner obscured by injuries in the type specimen. The Dakota specimen is perfectly preserved at this point, and displays a large convex sutural surface for the ischium, thus showing that my original description was imperfect in this point. The number of sacral vertebrae in the original specimen is not exactly determinable—only approximately, but this region is identical in character with that of other members of the family. That the Agathaumas silvestre is one of the largest species of the family is indicated by the following measurements of the Dakota specimen:

			mm.
Length of ilium			1465
Length of tibia			940
Diameters of tibia	{greatest proximal		325
	{greatest distal		290
Diameters of dorsal centrum		{anteroposterior
		vertical	138
		{transverse	137

The centrum of the dorsal vertebra is slightly opisthocoelous.